1. Field
This application relates to new chemical compounds, PARP-1 mutants and methods of use therewith. In some aspects, the present disclosure provides NAD analogs which may be used to determine the protein identity and the amino acid sequence wherein the ribosylation occurred.
2. Related Art
ADP-ribose is a naturally-occurring small molecule with a variety of functions. It is commonly found linked to proteins as a post-translational modification. Mono-ADP-ribose (MAR) and poly-ADP-ribose (PAR) transferase enzymes (generally known as PARP enzymes) catalyse the transfer (and in the case of PAR transferase enzymes, polymerization) of ADP-ribose units from NAD+, which can be covalently linked glutamate, aspartate, and lysine residues of acceptor proteins. DNA-strand breakage has been considered the main trigger of MAR and PAR synthesis, leading either to repair of the damaged site and cell survival, or cell death, depending on the cellular context and on the intensity of the DNA insult. However, other cellular components (e.g., interacting proteins, nucleosomes, posttranslational modifications, etc.) may also stimulate MAR and PAR synthesis and the size and branching of PAR synthesized under normal conditions is still unclear.
There are at present 18 PARP family members, and it remains to be determined whether all PARP family members can effectively synthesize MAR and/or PAR and, if so, whether the enzymes produce structures comparable to that synthesized by PARP1. Some PARP family members appear to lack conserved residues crucial for polymer elongation and may instead be mono(ADP-ribose) transferases. A detailed biochemical characterization of each PARP family member is necessary to answer the numerous questions that remain regarding PAR synthesis, transfer, function and degradation but mechanisms and methods to do so are still lacking. Thus, new compounds and methods to determine information about the activity of each PARP enzyme are needed.